Method for manufacturing a buried heterostructure laser diode

Abstract

A method for manufacturing a buried heterostructure laser diode comprising an active layer and a clad layer which are formed as a reverse mesa on a substrate, current blocking layers and an insulation layer deposited on the top of the blocking layers, and an electrode formed on the top thereof comprising: a first step for forming a SiO 2 stripe mask on the clad layer after a first liquid phase epitaxial growth of the active layer and the clad layer on the substrate, a second step for etching the clad layer under the SiO 2 stripe mask using an etchant to form a reverse mesa structure, a third step for selectively etching the clad layer using an etchant such as a family of hydrochloric acid and then for making the active layer protrude, and a fourth step for naturally melthig back the protruded porting of the active layer surface during the second epitaxial growth process is provided.

What is claimed is: 
     
       1. A method for manufacturing a buried heterostructure laser diode including a reverse mesa structure of an active layer (7) and a clad layer (4) formed on a substrate, current blocking layers (3) and (6) and an insulation layer (2) formed on the side of the mesa structure and an electrode (1) formed on the top of the mesa structure and an insulation layer, comprising: a first step of forming a SiO 2  stripe mask (8) on the clad layer (4) after the first liquid-phase epitaxial growth of the active layer (7) and clad layer (4) on the substrate:   a second step of etching them under the SiO 2  stripe mask (8) using an echant for form reverse mesa structure;   a third step of selectively etching the clad layer (4) using an etchant of hydrochloric acid family to protrude the active layer (7); and   a fourth step of naturally melting back the protruded portion of the active layer (7) during the second epitaxial growth for growing the current blocking layers.   
     
     
       2. The method of claim 1, wherein the active layer (7) and the clad layer (4) are formed of one of the III-V family composition semiconductor group such as InGaAsP/InP family, GaA1As/GaAs family and InGaAs/InP family.   
     
     
       3. The method of claim 1, wherein the active layer (7) and the clad layer (4) are formed of one of the II-VI family composition semiconductor group such as HgCdTe/CdTe family and PbSnTe family.   
     
     
       4. The method of claim 1, where in the fourth step, the protruded portion of the active layer (7) is melted back concurrently with the growth of the current blocking layers (3) and (6) using a solution for growing the first current blocking layer.   
     
     
       5. A method for manufacturing buried heterostructure laser diode including a reverse mesa structure of an active layer (7) and a clad layer (4) formed on a substrate, current blocking layers (3) and (6) and an insulation layer (2) formed on the side of the mesa structure and an electrode formed on the top of the mesa structure and the insulation layer, comprising: a first step of forming a SiO 2  stripe mask (8) on the clad layer (4) after the growth of the active layer (7) and the clad layer (4) on the substrate;   a second step of protruding the active layer (7) using an etchant with higher etching speed of the clad layer (4) than that of the active layer (7) when the active layer (7) and the clad layer (4) are etched to be a reverse mesa structure;   a third step of naturally melting back the protruded portion of the active layer (7) during the second epitaxial growth for growing the current blocking layers.   
     
     
       6. The method of claim 5, wherein the active layer (7) and the clad layer (4) are formed of one of the III-V family composition semiconductor group such as in GaAsP/InP family, GAA1As/GaAs family and InGaA1As/InP family.   
     
     
       7. The method of claim 5, wherein the active layer (7) and the clad layer (4) are formed of one of the II-VI family composition semiconductor group such as HgCdTe/CdTe family and PbSnTe family.   
     
     
       8. The method of claim 5, wherein in the fourth step, the protruded portion of the active layer (7) is melted back concurrently with the growth of the current blocking layers (3) and (6) using a solution for growing the first current blocking layer.